Mobile mine roof support



Dec. 16, 1969 w. WILKENLOH ET AL 3,484,071

MOBILE MINE ROOF SUPPORT Filed June 5, 1968 2 Sheets-Sheet 1 $6 0 firs an Dec. 16, 1969 w. WILKENLOH ET AL 3,484,071

MOBILE MINE ROOF SUPPORT 2 Sheets-Sheet 2 Filed June 5, 1968 United States Patent O Int. Cl. E04g 02; E2111 15/02 US. Cl. 248357 12 Claims ABSTRACT OF THE DISCLOSURE A mobile mine roof support wherein the sole plate carries several extensible and contractible pit props. The coupling between each prop and the sole plate comprises a male coupling member which is received in a socket in the top face of the sole plate and can be fitted snugly into the lower end portion of a sleeve which surrounds the respective prop and is movable between a lower end position in which it enters the socket and surrounds the associated male coupling member and a raised position in which it exposes the male coupling member and permits lateral movement of the prop through a channel which is machined into the top face of the sole plate. Each sleeve is separably coupled to a flexible Wall which is mounted on the sole plate.

BACKGROUND OF THE INVENTION The present invention relates to improvements in mobile mine roof supports of the type which can be used in longwall mining of coal or the like and wherein a sole plate which can be shifted along the floor of an underground excavation supports one or more extensible and contractible pit props for roof-engaging caps. More particularly, the invention relates to improvements in couplings which connect the props to the sole plate of a mobile mine roof support of the type known as a walking mine roof support.

In many presently known walking mine roof supports, the lower portions of pit props are received in sleeves which are rigidly or articulately connected to the sole plate. It is also known to provide the sole plate with concave recesses for spherical lower end portions of mine props or to weld to the sole plate sleeves which define concave sockets for spherical lower end portions of the respective props. Rings of elastic material are normally inserted between the sleeves and the props to permit some pivotal movements of props with reference to the sole plate.

A drawback of the above described conventional mine roof supports is that the separation of a prop from the sole plate consumes much time and involves heavy manual work or the use of specially built lifting machines. Such separation is necessary from time to time in order to inspect a prop, to replace a damaged prop, to replace a shorter prop with a longer prop or vice versa, or to replace a relatively weak prop with a stronger prop or the other way around. As a rule, the prop must be lifted above and away from the sole plate in order to be raised above the sleeve or to be withdrawn from the socket in the top face of the sole plate. Such lifting of a heavy and bulky prop invariably requires the use of complicated machinery which must be introduced into an underground excavation and manipulated in a space which hardly suffices to accommodate the mobile mine roof support. Furthermore, it happens frequently that the mine roof sags, especially if the support is held at a standstill for extended priods of time. Such sinking or sagging of the mine root" causes a shortening of the props in the mobile support to a minimum length and, consequently, the props cannot be lifted above the sole plate so that they cannot be separated at all. A hanging mine roof often exerts upon the caps of the props a pressure which prevents any lifting of the props above the sole plate. In such excavations, the material of the mine roof must be removed in the region above the props to provide room for lifting of the props above the sleeves or sockets of the sole plate. Such work consumes much time and is connected with danger to the persons in charge.

SUMMARY OF THE INVENTION It is an object of our invention to provide a mobile or walking mine roof support, particularly for use in long-wall mining of coal, wherein the props can be separated from the sole plate without any lifting above and away from the sole plate.

Another object of the invention is to provide novel coupling means between the props and the sole plate or plates of a mobile mine roof support.

A further object of the invention is to provide a mobile mine roof support wherein the props are separably and particularly coupled to the sole plate in a novel way and can be rapidly and conveniently separated from or reattached to the sole plate.

The improved mobile mine roof support comprises a sole plate whose top face is provided with a socket for each of the pit props, and a sleeve which surrounds each prop and 'is movable with respect thereto up and down so that its lower end portion may extend into or is withdrawn from the respective socket. When the lower end portion of a sleeve extends into the corresponding socket, the respective prop is held against lateral movement with reference to the sole plate and can be moved in an underground excavation in response to movement of the sole plate toward the mine face. When a sleeve is lifted to a raised position so that it is Withdrawn from the corresponding socket, it can be moved with the prop laterally of or in another direction with reference to the sole plate without necessitating any lifting of the prop.

The coupling between a prop and the sole plate preferably further comprises a male coupling member which is received in the respective socket with at least some freedom of lateral or radial movement and on which the lower end face of the prop rests when the sleeve extends into the socket. The lower end portion of the sleeve is open and accommodates the corresponding male coupling member when it extends into the socket. Furthermore, the top face of the sole plate is preferably provided with channels which extend between the sockets and the adjoining lateral edge faces of the sole plate and whose bottom surfaces are flush with or slightly below the top faces of the male coupling members so that each prop can be slid along the corresponding bottom surface laterally toward and beyond the adjoining edge face when its sleeve is withdrawn from the respective socket.

The upper portions of the sleeves are preferably separably and articulately connected to walls or like holders which are provided on and extend upwardly from the sole plate.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved mobile mine roof support itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, Will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary transverse vertical sectional view of a mobile mine roof support which embodies one form of our invention, the prop in this illustration being shown in a position it assumes when it is properly coupled to the sole plate;

FIG. 2 is a similar fragmentary transverse sectional view but showing a prop in uncoupled position during movement laterally of and away from the corresponding socket in the sole plate;

FIG. 3 is a schematic side elevational view of a second mine roof support with four props and with a slightly modified sole plate which is shown in partial section; and

FIG. 4 is a horizontal sectional view as seen in the direction of arrows from the line IVIV of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 1 and 2, there is shown a portion of a mobile mine roof support, also called walking mine roof support. Such supports are used in longwall mining of coal or the like and are normally operated by hydraulic means to advance stepwise toward a mine K face and to push or drag a conveyor which collects material that is being removed from the mine face.

The mine roof support of FIGS. 1 and 2 comprises a relatively thick sole plate of rectangular outline which rests on and can he slid along the mine floor and supports several extensible and contractible pit props 1, only one of these props being shown in FIGS. 1 and 2. The illustrated prop comprises two sections 2 and 3 which are telescoped into each other. The upper section 3 can move up and down to thereby change the level of its spherical head 4 which supports a roof-engaging cap 33 shown in FIG. 3. The section 2 constitutes a hydraulic cylinder and the section 3 constitutes the piston for the cylinder and is moved up in response to admission of a hydraulic pressure medium in av manner well known from the art and forming no part of the present invention. The prop 1 is extended when the cap 33 should engage and support the roof in an underground excavation as well as when the hydraulic advancing mechanism of the mine roof support should advance the aforementioned conveyor toward the mine face.

The present invention is concerned with a readily separable articulate coupling between the lower section or cylinder 2 of the prop 1 and the sole plate 5. The upper side or top face of the sole plate has a socket or recess 6 which is bounded by a concave surface and accommodates a centrally located hollow upright pivot member or post 7. The latter is surrounded by an annular male coupling member 9 which resembles a portion of a sphere and whose convex surface 9' abuts against the concave surface in the socket 6. The coupling member 9 has a central opening or hole 10 which accommodates the post 7 with a certain clearance so that the member 9 can move in all directions by sliding along the concave surface of the socket 6. The post 7 carries a ring-shaped retainer or washer 11 which is received in an internal groove 12 of the male coupling member 9 and serves to hold the surface 9 of the member 9 against movement away from the concave surface in the socket. A bolt 13 extends upwardly through the hollow post 7 and meshes with a nut 14 which holds the washer 11 against axial movement in upward direction. It will be noted that the underside of the washer 11 is convex and that such underside abuts against a concave surface in the groove 12 to permit some movements of the male coupling member 9 with reference to the sole plate and post 7. As stated before, the central opening of the male coupling member 9 is large enough to accommodate the post 7 with a certain amount of play, and the same applies for the groove 12 and washer 11.

The male coupling member 9 has a cylindrical peripheral surface 9" and its diameter is less than the diameter of the socket 6 so that an annular space develops around the peripheral surface 9" when the member 9 is properly accommodated and held in the socket 6. This annular space can receive the chamfered lower end portion 15 of a sleeve-like female coupling member 15 which surrounds the lower section 2 and is movable axially to enter into or to be withdrawn from the socket 6. Both ends of the sleeve 15 are open. When moved to its lower end position, the end portion 15' of the sleeve 15 surrounds the cylindrical peripheral surface 9" of the male coupling member 9 and thus couples the prop 1 to the sole plate 5 in such a way that the prop can swivel to the extent determined by the clearance between the male coupling member 9 and the parts 7, 11, 13 and 14.

The upper end portion of the sleeve 15 has a substantially U-shaped holder 16 whose base or web 17 is located in a substantially vertical plane and has a horizontal slot 17'. This slot 17' can permit passage of a fiat head 19 provided on a connecting bolt 18 which is separably connected to an elastically deformable upright carrier or wall 26 of the sole plate 5 by a nut 21. The head 19 can pass through the slot 17' in a predetermined angular position but engages with the base 17 of the holder 16 when moved from such angular position to thereby establish a connection between the wall 20 and the sleeve 15. A cushion 22 of rubber or other suitable elastomeric material is inserted between the base 17 and the wall 20 to enable the prop 1 to swivel with reference to the sole plate 5 even if the sleeve 15 is connected to the wall 20. when the lower end portion.15' of the sleeve 15 surrounds the peripheral surface 9", the bottom end face 2 of the lower prop section 2 rests on the horizontal top face 9" of the male coupling member 9. This top face 9" is coplanar with or is located at a level slightly above the bottom surface 23' in a transverse channel 23 which is provided in the top face of the sole plate 5 and extends from the socket 6 to a lateral edge face 5'. The configuration of the channel 23 is shown in FIG. 4.

In order to separate the prop 1 from the sole plate 5, the persons in charge must turn the head 19 of the connecting bolt 18 by degrees to a horizontal position so that the head is aligned with the horizontal slot 17' in the base 17 of the holder 16 on the sleeve 15. This is shown in FIG. 2. The head 19 is then moved axially of the bolt 18 to be withdrawn through the slot 17 and to permit lifting of the sleeve 15 in the direction indicated by arrow A. Such lifting results in a movement of the lower end portion 15' of the sleeve 15 above and away from the peripheral surface 9" of the male coupling member 9. In the next step, the prop 1 is pushed in the direction indicated by arrow B whereby the lower end face 2 of the section 2 slides off the top face 9" of the male coupling member 9 and onto the bottom surface 23' of the recess 23. Thus, the prop can be removed from the sole plate 5 without any lifting, i.e., merely by changing the angular position of the connecting bolt 18 and its head 19, by moving the bolt axially, by lifting the relatively lightweight sleeve 15 off the male coupling member 9, and by sliding or pushing the lower section 2 of the prop along the top face 9" and bottom surface 23.

The prop 1 is coupled to the base plate 5 by reversing the just mentioned steps. When the bottom end face 2 of the section 2 registers with and rests on the top face 9", the sleeve 15 is free to descend to the position shown in FIG. 1 and to prevent unintentional separation of the prop. The head 19 is then caused to enter the slot 17' and the bolt 18 is turned to prevent withdrawal of the head from the holder 16.

FIGS. 3 and 4 illustrate a slightly modified mobile mine roof support. The sole plate of this support differs from the sole plate 5 in that the sockets 35 constitute inserts which are received in vertical bores or holes 34 of the sole plate and are secured thereto by welding or in another suitable way. The inserts or sockets 35 have concave top faces abutting against convex bottom faces of male coupling members 9 which cannot be seen in FIGS. 3 and 4 because they are received in the open lower end portions of the respective sleeves 15. The holes 34 are surrounded by cylindrical surfaces.

The carriers or walls 20 for the two trailing props 1 of the support shown in FIGS. 3 and 4 constitute the flanges of a U-shaped bracket ZtlA which is afiixed to the rear portion of the sole plate 1435 and which is preferably elastic. The sleeves for the two front props 1 are coupled to a pair of flexible upright carriers or walls which are secured to the front portion of the sole plate 105 and whose top edges are connected to each other by a separable lid 24 having cutouts 25 large enough to afford access to the bolts 18 which connect the front sleeves 15 to the walls 20'.

The foremost portions of the walls 20 are provided with vertical ways 26 having V-shaped grooves 27 which receive with clearance a collar 29 provided on a doubleacting hydraulic cylinder 28 which forms part of the advancing means for moving the mine roof support along the mine floor and for advancing a material transporting conveyor 32 toward the mine face. The eye at the forward end of a piston rod 30 for the cylinder 23 is connected with the conveyor 32 by a separable coupling 31. The numeral 33 denotes in FIG. 3 one of two roof-engaging caps which are articulately connected to the heads 4 of two aligned props 1, i.e., to the head of a leading prop and to the head of a trailing prop. It is also possible to provide a separate cap for each prop 1 and to separably connect such caps to each other by means of articulate coupling which allow angular movements of caps in order to insure large surface-to-surface contact of caps with the mine roof.

The manner in which the mine roof support is advanced along the mine floor is well known and will be described only shortly. Thus, in order to advance the conveyor by a step toward the mine face (which is located to the right of the conveyor 32, as viewed in FIG. 3), the operators extend the props 1 so that the caps 33 bear against the mine roof and that the sole plate 165 bears strongly against the mine floor. The cylinder 28 then receives oil or other suitable pressure medium in a sense to expel the piston rod 30 forwardly whereby the piston rod pushes the conveyor 32 toward the mine face. In the next step, the props 1 are caused to contract so that the caps 33 move away from the mine roof and the cylinder 28 receives pressure medium in a sense to retract the piston rod 30. Since the conveyor 32 is rather heavy, the cylinder 28 travels toward the coupling 31 and entrains the sole plate 105 which slides along the mine floor. The props 1 are then extended again to properly support the mine roof during removal of material from the mine face Such material descends onto and is trans ported by the conveyor 32.

When a cap 33 is connected to one of the leading props and to the correspondiing trailing prop, these props can be separated from the sole plate as a unit. All that is necessary is to separate the corresponding sleeves 15 from the walls 2% and 2t and to thereupon lift the sleeves above the sockets of the sole plate so that the lower sections 2 of the props can slide along and beyond the respective bottom surfaces 23'. Thus, it is not even necessary to separate a cap 33 prior to separation of two props from the sole plate 105, and such separation of props requires no lifting whatever which is advantageous for reasons that were described hereinbefore. Such separation without any lifting of props is possible due to the fact that the sleeves 15 are movable up and down to respectively couple the props to and to disengage the props from the associated male coupling members 9 and sole plate 105. Furthermore, the sleeves 15 do not interfere with pivotal movements of props 1 with reference to the sole plate because the props rest on male coupling members 9 which are movable and turnable within limits determined by the dimensions of their openings 10 and grooves 12.

The sole plate 5 or may consist of relatively thick metallic sheet stock or the like. If each prop carries a separate cap and if such caps are articulately connected to each other, the connections between the caps are preferably of the readily separable type to allow for independent separation of each prop from the sole plate. The sole plate 5 or 105 can support three or more pairs of props. Alternatively, each prop can be coupled to a separate sole plate and such sole plates can be articulately connected to each other or to a centrally located main sole plate, not shown.

What we claim is:

1. In a mobile mine roof support, a combination comprising a sole plate; a mine prop supported by said sole plate; and coupling means separably connecting said prop to said sole plate, comprising a socket provided in said sole plate and a sleeve surrounding said prop and having a lower open end portion extending into said socket, said sleeve being movable upwardly along said prop to withdraw its lower end portion from said socket without moving said prop relative to said sole plate.

2. A combination as defined in claim 1, wherein said prop has a bottom face and said sole plate has a guide surface which is substantially coplanar with said bottom face and along which the prop is slidable on upward movement of said sleeve.

3. A combination as defined in claim 2, wherein said sole plate has an edge face, a top face into which said socket extends and a channel provided in said top face and extending between said socket and said edge face, said guide surface being the bottom surface of said channel.

4. A combination as defined in claim 1, wherein said socket has a concave upper surface and wherein said coupling means further comprises a male coupling member having a convex bottom surface abutting against said concave surface and having limited freedom of movement with reference to said sole plate, said male coupling member being received in said sleeve when the latter extends into said socket.

5. A combination as defined in claim 4, wherein said male coupling member has a cylindrical peripheral surface which is fitted into the lower end portion of said sleeve when the latter extends into said socket.

6. A combination as defined in claim 4, further comprising a centrally located pivot member secured to said sole plate and extending into said socket, said male coupling member having a centrally located opening receiving said pivot member with a predetermined clearance to permit radial movements of said male coupling member in said socket.

7. A combination as defined in claim 4, wherein said male coupling member has a substantially fiat top face and said prop has a substantially fiat bottom face resting on said top face when the lower end portion of said sleeve extends into said socket.

8. A combination as defined in claim 7, wherein said sole plate has a top face into which said socket extends, a lateral edge face and a channel extending between said edge face and said socket and having a bottom surface which is substantially coplanar with the top face of said male coupling member so that the bottom face of said prop can be moved along said bottom surface on upward movement of said sleeve to withdraw its lower end portion from said socket.

9. A combination as defined in claim 1, further comprising carrier means provided on and extending upwardly from said sole plate and connecting means securing an upper portion of said sleeve to said carrier means.

10. A combination as defined in claim 9, wherein said carrier means comprises a wall and said connecting means comprises elastic means permitting some pivotal movement of said sleeve with reference to said sole plate.

11. A combination as defined in claim 10, wherein said connecting means further comprises a slotted member mounted on said sleeve at a level above said lower end portion thereof, and a bolt mounted on said wall and movable with reference thereto between a first position in which it registers with and can pass through said slotted member and a second position in which it connects said wall to said slotted member.

12. A combination as defined in claim -11, wherein said slotted member has a substantially horizontal slot and said bolt has a head which can pass through said horizontal slot in said first position of the bolt.

References Cited UNITED STATES PATENTS 2,616,650 11/1952 Thompson 248-346 FOREIGN PATENTS 1,207,322 12/1965 Germany.

ROY D. FRAZIER, Primary Examiner 10 F. DOMOTOR, Assistant Examiner 

